Title of Invention

A SPINNING MACHINE HAVING A PLURALITY OF ADJACENTLY DISPOSED SPINNING STATIONS.

Abstract

This invention related to a spinning machine having a plurality of adjacently disposed spinning stations (1,2,3), each spinning station (1) having a drafting apparatus (4) comprising a front roller pair (7) which defines a front nipping line (13),a condensing zone (6) for condensing a drafted fibre strand (5) arranged downstream of the drafting apparatus (4), THE CONDESNING ZONE (6) comprises an air permeable trasport belt (15), which transports the fibre strand (5); a suction channel (17) which guides the transport belt (15) on a sliding surfae (16),and a sution slit (19) located in the sliding surface (16), the suction channel(17) extending along a plourality of spinning stations (1,2,3) projects into a wedge shaped gap (27) formed by the front roller pair (7), and the front roller pair(7) comprises a driven bottom cylinder (10) which extends along the plurality of spinning stations (1,2,3), the bottom cylinder 10'has a smaller diameter (d) between the spinning stations (1,2,3) than at the spinning stations (1,2,3). The suction channel (17) is configured at a technically closest possible location in the front nipping loine (13) and to the bottom cylinder (10) without actually touching them (13,10)and without significantly deflecfting the fibre strand (5) to be condensed in the area of the wedge shaped gap (27); and in that the bottom cylinder (10) has sufficiently large cleaning gap (28) in relation to the suction channel (17) between the spinning stations (1,2,3). Figure :1.

Full Text

BACKGROUND AND SUMMARY OF THE INVENTION Spinning machine comprising a plurality of spinning stations The present invention relates to a spinning machine having a plurality of adjacently arranged spinning stations each comprising a drafting apparatus including a front roller pair which defines a front nipping line, as well as a condensing zone for condensing a drafted fibre strand arranged downstream of the drafting apparatus, which condensing zone comprises an air-permeable transport belt which transports the fibre strand, a suction channel which guides the transport belt on a sliding surface, and a suction slit located in the sliding surface, whereby the suction channel, extending along a plurality of spinning stations, projects into a wedge-shaped gap formed by the front roller pair and whereby the front roller pair comprises a driven bottom cylinder which extends along a plurality of spinning stations, which bottom cylinder has a smaller diameter between the spinning stations than at the spinning stations. The fibre strand drafted in a drafting apparatus of a spinning machine subsequently recieves a spinning twist. If this spinning twist were imparted directly after drafting, then a so-called spinning triangle would occur at the front roller pair, which spinning triangle contains lateral fibres not completly bound into the twisted thread. In order to avoid this disadvantage, a so-called condensing zone has in recent times been arranged directly downstream of the drafting apparatus, in which condensing zone the drafted, but still twist-free fibre strand is bundled or condensed by means of a lateral collecting together of its single fibres, so that after the arranging of a further nipping point, the disadvantageous spinning triangle is no longer present. When the condensed fibre strand is then imparted its spinning twist in the usual way, a thread is created which is less hairy, more even and more tear-resistant. In a prior art spinning machine of the above mentioned type (German published patent application 198 37 179), a suction channel is arranged downstream of the front roller pair of the drafting apparatus, which suction channel is either at a large distance from the front nipping line, or it deflects to a great degree the fibre strand to be condensed directly downstream of the front nipping line. In the area of the wedge-shaped gap located between the front roller pair and the suction channel, in particular also between the individual spinning stations, fibres can collect, which for one reason or another were not bound into the fibre strand during condensing. These stray single fibres may at some time return to the fibre strand in an undesirable way and/or block the perforations of the air-permeable transport belt, both of which in time impair the condensing effect. This disadvantage cannot be eliminated in that in the known spinning machine the bottom cylinder has a somewhat smaller diameter between the spinning stations than at the spinning stations, where the bottom cylinder is provided with a fluting in a known way. The somewhat larger diameter at the fluting occurs from warping during the usual rolling of the fluting during manufacture. It is an object of the present invention to avoid stray fibres to the greatest extent possible, and when they do occur, to eliminate them from the areas of the spinning stations. This object has been achieved in accordance with the present invention in that the suction channel is positioned as near as is technically possible to the front nipping line and to the bottom cylinder without actually touching it and without deflecting the fibre strand to be condensed to any significant degree in the area of the edge-shaped gap, and in that the bottom cylinder leaves a sufficiently large cleaning gap between the spinning stations in relation to the suction channel. It has been shown, that fibre fly can be reduced in that the suction channel is arranged as closely as possible to the front nipping line and to the bottom cylinder, whereby naturally a certain necessary distance must be maintained. The arrangement of the components should be such that the fibre strand is deflected as little as possible after it leaves the front nipping line. Thus a fibre strand of a higher quality occurs from the outset. Any occuring stray fibres usually reach the cleaning gap located beside the spinning stations, which cleaning gap is formed outside of the spinning station between the bottom cylinder and the suction channel. Stray fibres can fall through this enlarged cleaning gap, which is significantly larger than the diameter alteration which in prior art occurs during manufacture of the fluting of the bottom cylinder, thus being removed from the critical area of the spinning stations. The bottom cylinder between the spinning stations is preferably reduced in diameter by means of metal cutting. It should be at least so far reduced that the cleaning gap has an inner width of at least 1.2 mm. Trials have shown that favourable ratios are given when the bottom cylinder at the spinning stations, that is in the area of its fluting, has a diameter of approximately 27 mm and bet- ween the spinning stations a diameter of approximately 24 mm. In order to remove stray fibres in a more reliable way, it can be additionally provided that the bottom roller touches the transport belt at a point where it is not supported opposite the suction channel. Thus an additional mechanical cleaning of the transport belt takes place, as the bottom cylinder and the transport belt run in opposite directions at the point of contact. BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein: Figure 1 is a part intersectional side view through a spinning station in the area of a condensing zone, Figure 2 is a view in the direction of the arrow II of Figure 1 onto the bottom cylinder and the condensing zone. DETAILED DESCRIPTION OF THE DRAWINGS In the case of the above mentioned spinning machine, a rinq spinning machine is preferably involved. It comprises in the usual way a plurality of adjacently arranged spinning stations in machine longitudinal direction, of which three spinning stations 1, 2 and 3 are visible in Figure 2. Each spinning station 1 comprises amongst other components a drafting apparatus 4, of which only the end area is shown in Figure 1, and a condensing zone 6 arranged downstream of the drafting apparatus 4, which condensing zone 6 bundles a drafted but still twist-free fibre strand 5. The remaining components of the spinning station 1 are not shown. Each drafting apparatus 4 comprises amongst other components a front roller pair 7 as well as an apron pair arranged upstream therefrom and comprising a lower apron 8 and an upper apron 9. The remaining roller pairs of the drafting apparatus 4 are not shown. The front roller pair 7 comprises a bottom cylinder 10 extending along a plurality of spinning stations 1,2,3 ..., which bottom cylinder 10 has in a known way a fluted area 11. At each spinning station 1, a top roller 12 is arranged to the fluted area 11 of the bottom cylinder 10 in a known way. The front roller pair 7 defines a front nipping line 13, at which the drafting zone of the drafting apparatus 4 ends. In the drafting apparatus 4, fed fibre material 14, for example a sliver or a roving, is drafted in transport direction A to the desired fineness. The drafting process ends essentially at the front nipping line 13. For the reasons mentioned above, a condensing zone 6 is arranged downstream of the drafting apparatus 4, in which condensing zone 6 the still twist-free fibre strand 5 is bundled or condensed by means of lateral collecting together of its single fibres. Each condensing zone 6 comprises an air-permeable transport belt 15, which transports the fibre strand 5 to be condensed through the condensing zone 6. In the case of the transport belt 15, a thin, close-meshed woven belt is preferably involved, in which the air permeability occurs naturally. The transport belt 15 is guided over a sliding surface 16, which is formed by the outer contour of a suction channel 17 extending along a plurality of spinning stations. The suction channel 17 is connected via a vacuum conduit 18 to a vacuum source (not shown). In the sliding surface 16 of each spinning station 1, a suction slit 19 is located, which is arranged slightly diagonally to the transport direction A and as a result of which is provided with a lateral gathering edge 20, along which the fibre strand 5 to be condensed travels. At this gathering edge 20, the fibre strand 5 is condensed by means of lateral collecting together of its single fibres, whereby in addition a very slight false twist is applied, which increases the condensing effect. The transport belt 15 is guided via a tensioning element 21 at a distance from the suction slit 19. A delivery roller 23 is arranged at the end of the condensing zone 6, which delivery roller 15 drives the transport belt 15 and forms with the suction channel 17 a delivery nipping line 24, to which the suction slit 19 extends and which forms a twist block with regard to the spinning twist. Directly downstream of the delivery nipping line 24 the thread 25 arises, while it is fed in delivery direction B to a twist device (not shown), for example a ring spindle. The delivery roller 23 prevents the spinning twist applied to the thread 25 from extending back into the condensing zone 6. A toothed belt drive 26, denoted only by a dot-dash line, serves the drive of the delivery roller 23 and is so designed that the delivery roller 23 has a slightly higher circumferential speed than the top roller 12. As can be seen from Figure 1, the front roller pair 7 forms on its side facing the condensing zone 6 a wedge-shaped gap 27, in which the suction channel 17 projects. The suction channel 17 should hereby be positioned as close to the front nipping line 13 and the bottom cylinder 10 as is technically possible, without coming into contact with the latter and without significantly deflecting the fibre strand 5 to be condensed in the area of the wedge-shaped gap 27. It has been shown that such an arrangement results in a particularly good quality thread 25. The close positioning should be such that between the suction channel 17 and the front nipping line 13 and the bottom cylinder 10 there is only a very small necessary distance. This close positioning of the suction channel 17 to the front roller pair 7 results in as few as possible stray fibres occuring which then leave the fibre strand 5. Should any stray fibres occur, care must be taken that these fibres do not get into the fibre strand 5 again in an undesirable way. For this reason it is provided that between the spinning stations 1,2,3 ...the bottom cylinder 10 has, in relation to the suction channel 17, a sufficiently large cleaning gap 28. This cleaning gap 28 should be significantly larger than the prior art diameter reduction, which is usually present in bottom cylinders 10 as a result of the standard application of the fluted area 11. The dimensions of the cleaning gap 28 are so chosen that any stray fibres fall through and are thus removed from the criticial area of the spinning station 1. The smaller diameter d of the bottom cylinder 10 is made preferably by means of a metal cutting process, whereby the diameter d should be reduced to such an extent that the cleaning gap 28 has an inner width a of at least 1.2 mm. Favourable conditions have arisen in practice when the bottom cylinder 10 has a diameter D in its fluted area 11 of approximately 27 mm and between the spinning stations 1,2,3... a diameter d of approximately 24 mm. The cleaning effect can be increased if the bottom cylinder 10 touches the transport belt 15 at a point 2 9 where it is not supported opposite the suction channel 17, where the bottom cylinder 10 and the transport belt 15 travel in opposite directions. An additional mechanical cleaning thus takes place. WE CLAIM 1. A spinning machine having a plurality of adjacently disposed spinning stations (1,2,3), each spinning station (1) having a drafting apparatus (4) comprising a front roller pair (7) which defines a front nipping line (13), a condensing zone (6) for condensing a drafted fibre strand (5) arranged downstream of the drafting apparatus (4), the condenshg zone (6) comprises an a"r-permeable transport belt (15) which transports the flbre strand (5); a suction channel (17) which guides the transport bet (15) on a sliding surface (16); and a suction slit (19) located in the sliding surface (16), the suction channel (17), extending along a plurality of spinning stations (1,2,3), projects into a wedge-shaped gap (27) formed by the front roller pair (7), and the front roller pair (7) comprises a driven bottom cylnder (10) which extends along the pluralty of spinning stations (1,2,3), the bottom cylinder (10)" has a smaller diameter (d) between the spinning stations (1,2,3) than at the spiinhg stations (1,2,3), characterized in that the suction channel (17) is configured at a technically closest possfele location to the front nipping line (13) and to the bottom cylinder (10) without actually touching them (13,10) and without significantly deflecting the fibre strand (5) to be condensed in the area of the wedge-shaped gap (27); and in that the bottom cylnder (10) has a sufficiently targe cleaning gap (28) in relation to the suction channel (17) between the spinning stations (1,2,3). 2. A spinning machine as claimed in claim 1, wherein the bottom cylinder (10) is reduced in diameter between the spinning stations (1,2,3) by means of a metal cutting process. 3. A spinning machine as claimed h claim 1 or 2, wherein the cleaning gap (28) has an inner width (a) of at least 1.02 mm. 4. A spinning machine as claimed in claim 3, wherein the bottom cylinder (10) has a diameter (D) at the spinning stations (1,2,3) of 27mm and between the spinning stations (1,2,3}, a diameter (d) of 24 mm. 5. A spinning machine as claimed in any one of the claims 1 to 4, wherein the bottom cylinder (10) touches the transport belt (15) at a point (29) where it is not supported opposite the suction channel (17). This invention relates to a spinning machine having a plurality of adjacently disposed spinning stations (1,2,3), each spinning station (1) having a drafting apparatus (4) comprising a front roller pair (7) which defines a front nipping line (13), a condensing zone (6) for condensing a drafted fibre strand (3) arranged downstream of the drafting apparatus (4), the condensing zone (6) comprises an air-permeable transport belt (15) which transports the fibre strand (5); a suction channel (17) which guides the transport belt (15) on a sliding surface (16); and a suction slit (19) located in the sliding surface (16), the suction channel (17), extending along a plurality of spinning stations (1,2,3), projects into a wedge-shaped gap (27) formed by the front roller pair (7), and the front roller pair (7) comprises a driven bottom cylinder (10) which extends along the plurality of spinning stations (1,2,3), the bottom cylinder 10 has a smaller diameter (d) between the spinning stations (1,2,3,) than at the spinning stations (1,2,3). The suction channel (17) is configured at a technically closest possible location in the front nipping line (13) and to the bottom cylinder (10) without actually touching them (13,10) and without significantly deflecting the fibre strand (5) to be condensed in the area of the wedge—shaped gap (27); and in that the bottom cylinder (10) has a sufficiently large cleaning gap (28) in relation to the suction channel (17) between the spinning stations (1,2,3).

Documents:

262-cal-2001-granted-abstract.pdf

262-cal-2001-granted-assignment.pdf

262-cal-2001-granted-claims.pdf

262-cal-2001-granted-correspondence.pdf

262-cal-2001-granted-description (complete).pdf

262-cal-2001-granted-drawings.pdf

262-cal-2001-granted-form 1.pdf

262-cal-2001-granted-form 18.pdf

262-cal-2001-granted-form 2.pdf

262-cal-2001-granted-form 26.pdf

262-cal-2001-granted-form 3.pdf

262-cal-2001-granted-form 5.pdf

262-cal-2001-granted-form 6.pdf

262-cal-2001-granted-letter patent.pdf

262-cal-2001-granted-priority document.pdf

262-cal-2001-granted-specification.pdf